1. Field of the Invention
The present invention relates to the design of digital recording and playback systems. More specifically, the present invention pertains to the processing of voice and concurrent generation of corresponding text in a portable digital appliance.
2. Related Art
The use of portable digital recording and playback devices are quickly gaining popularity in business and among individual users. In particular, one attractive feature of digital recording is the possibility of converting the voice messages into text, which can then be reviewed, revised and incorporated into documents or otherwise retrieved for use subsequently. Today, there are several models of portable digital recorder in the marketplace. These prior art recorders typically record voice messages as compressed digital data. In order to convert the compressed digital data to text data, a separate computer program is generally required. Thus, in the prior art, subsequent to a recording session, the user needs to post-process the compressed digital data to perform the voice-to-text conversion. This requires additional processing time, and in some cases even requires the user to transfer the compressed digital data from the portable device to a personal computer (PC) having the necessary software program before the conversion can be performed. It is desirable to eliminate the extra step of post-recording conversion from compressed digital data to text data in a portable digital recording and playback system.
These prior art devices are not well-suited for generating text data from the recorded voice data for an additional reason. In order to achieve good conversion from voice to text, a high quality voice input to the voice to text conversion engine is needed. In prior art portable systems, the voice data is subject to high compression because portable systems typically have limited memory capacity, and high compression allows more voice data to be stored into the limited memory resources. Since voice data is stored in a highly compressed format in these portable prior art devices, the text data generated directly from the compressed voice data by a conversion program is usually unsatisfactory. As such, it is highly advantageous to have a portable digital recording and playback system which provides high quality conversion from voice to text.
Furthermore, portable devices are typically battery-powered. Thus, the need to conserve power is a major design consideration. As such, while a high capacity stager can potentially be used in a large, non-portable device deriving its power from a power outlet to improve the quality of the conversion from compressed voice data to text data, it is not a viable option in a portable device. Therefore, there exists a need for a portable digital recording and playback system which provides high quality conversion from voice to text and yet does not require a high rate of power consumption.